just installed my downpipe, and after the car warms up, I sometimes smell some type of burnt plastic odor, any ideas?

 

Could be the gasket or gasket sealent burning up. It's normal. It should go away after a bit.

 

More than likely just you greasy fingerprints all over the pipe burning off, the penetrating oil from the original studs when you soaked it all down the night before, or just the new gasket smell. If it smell like that after a day the I'd be worried, but for now, fuhget aboutit.

Frank

Ooh, check to be sure your O2 sensor wire isn't touching!

 

you get that nasty smell after any mod on the exhaust as vudoodoodoo said it will pass